Suddenly my scalp is itching all over my head and i have a rash on my lower head to my neck and above my ears. i have no idea whats going on or if its an allergy ?

Scalp rash: I would think of an allergic reaction to something that came in contact with your scalp, scalp psoriasis or seborrheic dermatitis as possibilities. Can you think of a trigger such as a shampoo, cosmetics,hair spray? I recommend taking an antihistamine like benadryl (can cause drowsiness) or claritin(nondrowsy). If rash persists, consult a dermatologist for diagnosis and treatment.